1. Field of the Invention
This invention relates to a pipe joint mechanism for improved connection of branch pipes to, and fitting or replacement of valves and other equipment in a pipeline disposed in a building or in a soil layer, and is directed to provide a joint which facilitates and simplifies work required when part of an existing pipeline is connected to another pipe for partial repair or the like or when a valve, a meter or a flange is fitted to the pipeline or replaced.
2. Description of Related Art
Various joints have been proposed and put to practical use in the past which have been employed for partial improvement to, connection of branch pipe to and fitting or replacement of equipment such as a valve in a pipeline. Typical examples of such conventional joints employed for such purposes are illustrated in FIGS. 8 through 11 of the accompanying drawings.
In the joint shown in FIG. 8, a packing 22 is interposed between joint members 20 and 20 each having a screw portion 21 for meshing with a main pipe that forms a pipeline and a connecting ring 23 is anchored to a step portion 24 of one of the members 20 and is meshed at 25 with the other member 20.
In the joint shown in FIG. 9, ring-like grooves 32, 32 engaging with a ring chip 29 and a fitting confirmation line 33 are formed on a main pipe 26, a ring packing 31, a movable ring 30 and the ring chip 29 are sandwiched between a nut 28 engaging with a female screw portion of a main body 27 and the main body 27. The insertion depth of the main pipe 26 is determined by the fitting confirmation line 33, the nut 28 is screwed in while the ring chip 29 and the ring-like grooves 32, 32 are being aligned to one another, the main pipe 26 is clamped and restricted by the ring chip 29 and seal is effected by the ring packing 31.
In the joint showing in FIG. 10, nut members 36, 36 are each fitted to either side of an intermediate member 35, a main pipe is inserted up to step portion 37, 37 formed in the intermediate member 35 and after a packing is interposed, each nut member 36 is screwed so as to attain a seal on the outer surface of the main pipe by the packing.
In the joint shown in FIG. 11, a nut member 43 is set over two joint members 42, 42 interposing a seal member 41 such as an O-ring between their joint surface or in other words, the nut member 43 is anchored to an anchor step 45 formed on one (42) of the joint members and screwed to the other joint member 42. The main pipe to be connected is inserted into a fitting portion 44 in both joint members 42 and is welded around its entire periphery at the end portions 46 of the joint members 42.
In the conventional joints such as described above, however, their connecting works or operations are complicated and man-hours inevitably great.
In the joint shown in FIG. 8, a male screw must be threaded on the main pipe to be connected in order to screw-fit the joint member 20 to the screw portion 21 and in order to form such a male screw, the main pipe which has been laid down and kept under fixed state must be taken out over a considerable length or must be arranged so that a threading tool can be fitted to it and operated before the male screw is threaded. This means that a wall or soil layer must be broken to take out the main pipe or to establish the state where the threading tool can be fitted and operated, and the extent of the subsequent repair becomes essentially very great. Accordingly, many man-hours and quantities of materials are required for the repair.
In the joint shown in FIG. 9, too, the main pipe 26 must be taken out over a considerably great length so as to form the ring-like grooves 32, 32 meshing with the ring chip 29 and the fitting confirmation line 33. Therefore, the wall or soil layer must be broken over a considerably great range to take out the main pipe and the pipeline must then be repaired in the same way as the joint shown in FIG. 8.
In the joint shown in FIG. 10, a small diameter portion 38 which is in alignment with the inner diameter of the main pipe must be formed at the center portion of the intermediate member 35 so as to make the flow of a fluid from the main pipe smooth. Therefore, even if the end portion of one of the main pipes can be inserted by sliding the intermediate member 35, the other pipe cannot be inserted up to the step portion 37 because that main pipe is kept under the fixed state. Therefore, a large-scale moving operation is necessary for at least the other main pipe and many man-hours are inevitably required.
Since the joint shown in FIG. 11 includes two joint members 42, fixing by welding must be carried out carefully to assure water-tightness between these two joint members 42, 42 and the main pipe, respectively. Therefore, a space sufficient enough to operate a welding rod around the entire periphery of each portion and many man-hours are inevitably required.